Problem: Solve for $x$ : $7x - 1 = 9x + 7$
Explanation: Subtract $7x$ from both sides: $(7x - 1) - 7x = (9x + 7) - 7x$ $-1 = 2x + 7$ Subtract $7$ from both sides: $-1 - 7 = (2x + 7) - 7$ $-8 = 2x$ Divide both sides by $2$ $\dfrac{-8}{2} = \dfrac{2x}{2}$ Simplify. $-4 = x$